In order to keep up with the increasing demands of the golfing public for more technology and performance from their iron type golf club heads, golf club designers have been forced to change the design of iron type golf club heads away from traditional muscle back construction in order to keep up with this trend.
One of the earliest attempts to improve the performance of the iron was to improve the moment of inertia of a golf club head by adding weight to the perimeter of the golf club head to create more forgiveness in off-center shots. U.S. Pat. No. 4,826,172 to Antonious provides an illustration of this technology by showing a perimeter weighted iron-type golf club head with a recessed or cavity back and a peripheral mass having an improved weight configuration.
Another way to improve the forgiveness of an iron type golf club head in addition to removing weight from the central portion and moving it out on the perimeter as illustrated above is to use exotic materials that are heavier than steel. The utilization of exotic materials that are heavier than steel allows more discretionary weight to be created in the same footprint, further improving the performance of an iron type golf club head. U.S. Pat. No. 3,845,960 to Thompson illustrates this principle by placing tungsten powder at the heel and toe end of the golf club head to improve the moment of inertia of the golf club head.
With the development of more advanced materials, the infatuation with lightweight materials such as carbon fiber composite has also worked its way into golf club design, creating yet another way to improve upon the forgiveness of an iron type golf club head. U.S. Pat. No. 4,664,383 to Aizawa provides an early example of this by creating a golf club with resin with woven material as well as resin with non-oriented fibers to create a golf club head.
In addition to making the golf club more forgiving as shown by the three above examples, another way to improve the performance of an iron type golf club head is to improve the ballspeed of the iron type golf club head. One way to achieve this is to decrease the thickness of the striking face of the golf club head. U.S. Pat. No. 6,592,469 to Gilbert provides an example of this technology by teaching a golf club with a thin front face for striking a golf ball and a peripheral weighting surrounding the back of the front face and defining a cavity.
Despite all the attempts to improve the performance of an iron type golf club, none of the designs have been able to combine all of the best characteristics of each individual technology in one compact convenient package. More specifically, none of the designs incorporate advanced material technology to increase the forgiveness and ballspeed of the iron type golf club head in one unitary golf club chassis without sacrificing the aesthetic appeal of the golf club.